Anamorphic lens

ABSTRACT

An anamorphic lens includes a cylindrical lens group arranged in a direction from an object side to an image side. The cylindrical lens group includes an anamorphic group and together form an imaging group. The anamorphic group includes a first lens, a second lens, and a third lens arranged in a direction of an object side to an image side. The second lens and the third lens may be joined together and the first lens may be a negative optical power biconcave cylindrical lens. Through the optical characteristics of the cylindrical lens in the anamorphic group, the entering horizontal light is compressed while the vertical light path maintains unchanged. The imaging group comprehensively corrects the light so that the horizontal field of view angle is increased by about 33% to achieve a magnification by 1.33 times for an anamorphic shooting.

TECHNICAL FIELD

The present invention relates generally to the field of lens technology,and in particular, to an anamorphic lens.

BACKGROUND

With the rapid development of web technology, taking photos and videoshas become essential part for ordinary consumers. With the promotion of5G and other technologies in recent years, more and more video sharingsuch as Vlog has been used. More individuals shoot short films and micromovies with mobile phones, cameras and other tools.

However, the current normal shooting screen ratio of mobile phones,tablets, cameras and other devices on the market is 16:9, but thecinematic widescreen video ratio is 2.4:1. Therefore, users need tomanually edit or digitally cropping method to edit the captured imagesor videos. However, the pixels of the pictures are sacrificed duringcropping or editing.

Some professional anamorphic lens brands such as, Hawk from Germany,Cooke from Great Britain, ARRI from Germany, Panavision from the USA,Angenieux from France and SLR from Hong Kong are usually tailored forprofessional customers. The prices of these film equipment are generallyover tens of thousands of dollars or even more expensive, and anamorphiclenses themselves weighs several kilograms.

Expensive and quality professional anamorphic lenses are not suitablefor ordinary users. Therefore, how to reduce the size of anamorphic lensand reducing the weight of the lens are technical problems that are tobe solved at present embodiments of the invention.

SUMMARY

Therefore, embodiments of the invention attempt technically solveshortcomings in the professional anamorphic lens where the quality isgreat but at a cost that ordinary consumers could not afford. Aspects ofthe invention provide an anamorphic lens that solve the technicalproblem with the following embodiments:

An anamorphic lens may include cylindrical lens group in an arrangementof an object side to an image side. The cylindrical lens group mayinclude an anamorphic group of cylindrical lenses and an imaging grouphaving spherical lenses. The anamorphic group may include a first lens,a second lens and a third lens in a sequential order from the objectside to the image side. The second lens may be a negative optical powercylindrical lens and the third lens may be a positive optical powercylindrical lens.

In one embodiment, the first lens may be a negative optical powerbiconcave cylindrical lens.

In another embodiment, the second lens and the third lens may be joinedtogether.

The imaging group in a direction of light toward the image side maydispose a fourth lens, a fifth lens, a sixth lens, a seventh lens, aneighth lens, a ninth lens, and a tenth lens. In one embodiment, thefourth lens may be a positive optical power meniscus spherical lens; thefifth and eighth lenses may be positive optical power; the sixth lensand the seventh lens may be negative optical power spherical lenses; theninth lens may be a positive power biconvex spherical lens, and thetenth lens may be a positive power meniscus spherical lens.

In one embodiment, the fifth lens and the sixth lens may be joinedtogether. In such an arrangement, the fifth lens may be a positiveoptical power, and the sixth lens may be a negative optical power lens.

In one embodiment, the fifth lens and the sixth lens may be independentof each other. In such an arrangement, the fifth lens may be a positiveoptical power meniscus lens, the sixth lens may be a negative opticalpower meniscus lens. In one embodiment, the concave surfaces of thefifth lens and the sixth lens may be disposed toward the image side.

In one embodiment, the power distribution of the lenses constituting theanamorphic group and the lenses constituting the imaging group maypossess the following relationship:

500<abs(f ₁₋₃ /f ₄₋₁₀);

45<f ₄₋₁₀<55;

1.60<f ₄₋₆ /f ₄₋₁₀<2.10;

0.60<f ₇₋₁₀ /f ₄₋₁₀<0.80;

In another embodiment, the power distribution of the lenses constitutingthe anamorphic group and the lenses constituting the imaging group mayalso possess the following relationship:

1.10<abs(f ₁ /f ₂₋₁₀)<1.40;

−0.80<f ₁ /f ₂₋₃<−0.70;

0.50<f ₄ /f ₄₋₆<0.80;

1.0<f ₉₋₁₀ /f ₇₋₁₀<1.60;

5.0<abs(f ₇₋₈ /f ₇₋₁₀)<9.0;

Where, f may represent a focal length of the lens in X direction, wherethe subscript number of f represents a number of the ten lenses of theanamorphic lens. For example, f₁ may be the focal length in the Xdirection of the first lens, and f₁₋₁₀ may be the combined focal lengthof the first to 10th lenses in the X direction of ten lenses, and so on.

In yet another embodiment, the length of the anamorphic lens may be lessthan 105 mm, and the large outer diameter of the anamorphic lens may beless than 70 mm.

In a further embodiment, the focal length in the Y direction of theanamorphic lens may be 50 mm, and the aperture may be an f-stop of 1.8.

In a further embodiment, the mass of the anamorphic lens may be lessthan 600 g.

The technical solution of the present invention may include thefollowing advantages:

1. An anamorphic lens as provided by embodiments of the presentinvention may include a cylindrical lens arranged from the object sideto the image side as an anamorphic group and an imaging group includingspherical lenses. The anamorphic group may include a first lens, asecond lens, and a third lens that are disposed in a sequential order,and the second lens and the third lens may be joined together. The firstlens may be a negative optical power biconcave cylindrical lens, thesecond lens may be a positive optical power cylindrical lens and thethird lens may be a positive optical power cylindrical lens.

Use the optical characteristics of the cylindrical lenses in theanamorphic group to “compress” the horizontally entering light while thelight entering in the vertical direction remains unchanged, the imaginggroup thereafter may comprehensively correct the light passingtherethrough. Such aspects may increase the angle of field of view forthe horizontal shooting of the lens, which may increase the width thefield of the actual shot or filming. Aspects of the invention no longerneed post-processing or editing of the images or films, so that usersmay still obtain a ratio of 2.4:1 for a widescreen video or photoswithout sacrificing pixels as a result of the editing. At the same time,because the anamorphic group may be include a cylindrical lens, theanamorphic lens of embodiments of the invention may further include anoval shaped out-of-focus flare, sci-fi line flare, and other opticalcharacteristics in addition to the anamorphic function.

2. The anamorphic lens as provided by embodiments of the presentinvention may include the power distribution relationship of the lens inthe anamorphic group, and the lens in the imaging group:

500<abs(f₁₋₃/f₄₋₁₀); 45<f₄₋₁₀<55; 1.60<f₄₋₆/f₄₋₁₀<2.10;0.60<f₇₋₁₀/f₄₋₁₀<0.80; 1.10<abs(f₁/f₂₋₁₀)<1.40; −0.80<f₁/f₂₋₃<−0.70;0.50<f₄/f₄₋₆<0.80; 3.0<f₁₀/f₇₋₁₀<4.50; 1.10<abs(f₂₋₁₀/f₁₋₁₀)<1.60;where, f may represent a focal length of the lens in X direction, wherethe subscript number of f represents a number of the ten lenses of theanamorphic lens. For example, f₁ may be the focal length in the Xdirection of the first lens, and f₁₋₁₀ may be the combined focal lengthof the first to 10th lenses in the X direction of ten lenses, and so on.

Embodiments of the invention may increase the field of view of 50 mmf/stop of 1.8 half-frame lens horizontally by 33%, while the verticalfield of view may remain the same, resulting in a smaller sized 50 mmlarge aperture anamorphic lens.

DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific embodiments of thepresent invention or the technical solutions in the prior art, thedrawings needed to be used in embodiments or the description of theprior art are briefly introduced below. Obviously, the drawings in thefollowing are some embodiments of the present invention. For those ofordinary skill in the art, other drawings may be obtained based on thesedrawings without undue creative labor.

FIG. 1 is an optical structure diagram in an X direction according to afirst embodiment of the present invention;

FIG. 2 is an optical structure diagram in an Y direction according to afirst embodiment of the present invention;

FIG. 3 is an optical structure diagram in an X direction according to asecond embodiment of the present invention;

FIG. 4 is an optical structure diagram in an Y direction according to asecond embodiment of the present invention;

The following lists the labels for the reference numbers:

1—first lens; 2—second lens; 3—third lens; 4—fourth lens; 5—fifth lens;6—sixth lens; 7—seventh lens; 8—eighth lens; 9—ninth lens; 10—tenthlens; 11—anamorphic group lens; 12—imaging group.

DETAILED DESCRIPTION

The technical solution of the present invention may be clearly andcompletely described below with reference to the accompanying drawings.Obviously, the described embodiments may be part of the presentinvention, but not all of them. Based on the embodiments of the presentinvention, all other embodiments obtained by a person of ordinary skillin the art without creative efforts shall fall within the protectionscope of the present invention.

In the description of the present invention, it is noted that the terms“center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”,“inside”, “outside”, etc., are meant to indicate orientation orpositional relationship and they may be based on the orientation orpositional relationship shown in the drawings, and may only be for theconvenience of describing the present invention and simplifieddescription, and does not indicate or imply that the device or elementreferred to must have a specific orientation, a specific constructionand operation as they are not be construed as limiting the invention. Inaddition, the terms “first,” “second,” and “third” may be used fordescriptive purposes only, and should not be construed to indicate orimply relative importance.

In the description of embodiments of the present invention, it is notedthat the terms “installation”, “connected”, and “connected” should beunderstood in a broad sense unless otherwise specified and limited. Forexample, they may be fixed connections or removable, connected orintegrated; it may be mechanical or electrical; it may be directlyconnected, or it may be indirectly connected through an intermediatemedium, or it may be the internal communication of two elements. Forthose of ordinary skill in the art, the specific meanings of the aboveterms of embodiments of the present invention may be understood in acase-by-case basis.

In addition, the technical features involved in the differentembodiments of the present invention described below may be combinedwith each other as long as they do not conflict with each other.

Example 1

As shown in FIG. 1 and FIG. 2, one embodiment may include a 50 mmhalf-frame large aperture anamorphic lens. In one embodiment, the lensdescribed below may be transparent lens. The anamorphic lens may includeten lenses arranged along the optical path from an object side to animage side, which may include a first lens 1, a second lens 2, a thirdlens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens7, an eighth lens 8, a ninth lens 9, and a tenth lens 10.

In one embodiment, the first lens 1, the second lens 2, and the thirdlens 3 may be cylindrical lenses. The second lens 2 and the third lens 3may be joined together. Together with the first lens 1 to form ananamorphic group 11. The fourth lens 4, the fifth lens 5, the sixth lens6, the seventh lens 7, the eighth lens 8, the ninth lens 9, and thetenth lens 10—these seven lenses—in one embodiment, may be sphericallens. The fifth lens 5 and the sixth lens 6 may be joined together, andthe seventh lens 7 and the eighth lens 8 may be joined together. Theseseven lenses may form an imaging group 12.

In one embodiment, the first lens 1 may be a negative optical powerbiconcave cylindrical lens. The second lens 2 may be a negativecylindrical lens, and the third lens 3 may be a positive optical powercylindrical lens. The fourth lens 4 may be a positive optical powermeniscus spherical lens, and a concave surface of the fourth lens 4 isdisposed toward the image side.

In a further embodiment, the fifth lens 5 may be a positive opticalpower spherical lens. The sixth lens 6 and the seventh lens 7 may benegative optical power spherical lenses. The ninth lens 9 may be apositive optical power biconvex spherical lens. The tenth lens 10 may bea positive optical power meniscus spherical lens, and the convex surfaceof the tenth lens may be convex\ toward the object side.

In one embodiment, the lenses may be joined together as a unit. In thisembodiment, the second lens 2 and the third lens 3 may be joinedtogether. The fifth lens 5 and the sixth lens 6 may be joined together,and the seventh lens 7 and the eighth lens 8 may be joined together.Therefore, the anamorphic lens of this embodiment may comprise 10elements and 7 groups.

In a further embodiment, the combinations of the second lens 2 and thethird lens 3, the sixth lens 6 and the seventh lens 7, and the eighthlens 8 and the ninth lens 9 are not specific limitation. For example, inthis Example, the joining method may be via bonding. As an alternativeembodiment, based on the spirit and scope of the present invention, inorder to distinguish it from embodiments of the present application, theabove-mentioned combination methods may be modified, such as lamination,gluing, integrated molding, or the like. After such bonding, the shapeof the composite or combined lens may then be appropriately adjustedaccording to the above examples. Therefore, these alternative approachesmay also be within the scope and spirit of the invention.

In a further embodiment, the Example may provide that the fourth lens 4in the imaging group may be an independent lens. As an alternativeembodiment, the fourth lens 4 may be split to two, multiple lenses oruse two or multiple lenses joined together as a replacement. Whenreplacing the fourth lens 4, as long as the replacement lens satisfy theoptical power relationship, for example, “0.60<f₄/f₄₋₆<0.90”. Therefore,on the basis of the Example, any attempt to distinguish over the presentinvention by replacing lenses based on the number of lenses or acombination thereof are within the conception of the present applicationand should still fall within the spring and scope of the presentinvention.

In a further embodiment, the Example may provide that the fifth lens 5and the sixth lens 6 be joined together. As an alternative embodiment,the fifth lens 5 and the sixth lens 6 may be split into two or moreindependent lenses. In yet another embodiment, the joined lenses of thefifth lens 5 and the sixth lens 6 may be replaced with a single lens.Therefore, on the basis of the Example, any attempt to distinguish overthe present invention by replacing the fifth lens 5 and the sixth lens6, regardless of whether the lens type or shape has changed, or it is anindependent lens or a combined lens, as long as the replacement lenssatisfy the optical power relationship, for example,“0.60<f₄/f₄₋₆<0.90,” then such replacement still falls within the springand scope of the present invention.

In a further embodiment, the Example may provide that the seventh lens 7and the eighth lens 8 be joined together. As an alternative embodiment,the seventh lens 7 and the eighth lens 8 may be split into two or moreindependent lenses. In yet another embodiment, the joined lenses of thefifth lens 5 and the sixth lens 6 may be replaced with a single lens.Therefore, on the basis of the Example, any attempt to distinguish overthe present invention by replacing the fifth lens 5 and the sixth lens6, regardless of whether the lens type or shape has changed, or it is anindependent lens or a combined lens, as long as the replacement lenssatisfy the optical power relationship, for example,“5.0<abs(f₇₋₈/f₇₋₁₀)<9.0,” then such replacement still falls within thespring and scope of the present invention.

In a further embodiment, the Example may provide that the ninth lens 9and the tenth lens 10 be independent of each other. In one embodiment,the ninth lens 9 and the tenth lens 10 may satisfy an optical powerrelationship of “1.0<f₉₋₁₀/f₇₋₁₀<1.60”. Therefore, on the basis of theExample, any attempt to replace the ninth lens 9, the tenth lens 10 witha composite lens with multiple lenses joined together, a single lens,regardless of whether the lens type or shape has changed, or through acombination to modify it, still falls within the spring and scope of thepresent invention.

In one embodiment, specific numerical values of the actual parameters ofeach lens are not specifically limited. In this embodiment, the power ofeach lens or lens group may satisfy the following mathematicalrelationship:

500<abs(f ₁₋₃ /f ₄₋₁₀);

45<f ₄₋₁₀<55;

1.60<f ₄₋₆ /f ₄₋₁₀<2.10;

0.60<f ₇₋₁₀ /f ₄₋₁₀<0.80;

each lens's optical power further may satisfy the following mathematicalrelationship;

1.10<abs(f ₁ /f ₂₋₁₀)<1.40;

−0.80<f ₁ /f ₂₋₃<−0.70;

0.60<f ₄ /f ₄₋₆<0.90;

1.0<f ₉₋₁₀ /f ₇₋₁₀<1.60;

5.0<abs(f ₇₋₈ /f ₇₋₁₀)<9.0;

Where, f may represent a focal length of the lens in X direction (e.g.,horizontal direction), where the subscript number of f represents anumber of the ten lenses of the anamorphic lens. For example, f₁ may bethe focal length in the X direction of the first lens, and f₁₋₁₀ may bethe combined focal length of the first to 10th lenses in the X directionof ten lenses, and so on.

The following table may The actual parameters of each lens of thisembodiment that meet the above mathematical relationship are listedbelow:

Thick- Refrac- Surface radius ness tive Abbe Mass Lens Shape (mm) (mm)index Number (g) First lens Cylindrical −68.330 7.460 1.5113 67.60 40.2Cylindrical 53.600 5.827 Second lens Cylindrical inf 12.000 1.8325 20.1160.4 Third lens Cylindrical 31.100 8.000 1.9235 26.00 38.2 Cylindrical−88.300 1.260 Fourth lens Spherical 29.570 4.520 1.9108 35.25 16.5Spherical 66.000 0.220 Fifth lens Spherical 22.467 5.660 1.6968 55.538.5 Sixth lens Spherical 203.000 3.030 1.6435 28.63 9.6 Spherical 13.1663.444 Light bar 10.719 Seventh lens Spherical −15.270 1.580 1.6612 27.244.8 Eighth lens Spherical 95.000 10.350 1.8040 46.60 10.2 Spherical−27.650 0.200 — Ninth lens Spherical 131.600 4.450 1.8040 46.60 8.2Spherical −69.800 0.100 Tenth lens Spherical 89.800 9.420 1.8040 46.6023.2 Spherical inf

In one aspect, the first lens 1 may be a large Abbe numberlow-dispersion lens.

In one aspect, before applying the anamorphic lens of the invention, afield of view of a given 50 mm lens with f/stop of 1.8 as the focallength is: V (vertical) 18.25 degree, H (horizontal) 27.04 degree.

After applying the anamorphic lens of embodiments of the invention, thefield of view of the given 50 mm lens with f/stop of 1.8 as the focallength is: V (vertical) 18.25 degree, H (horizontal) 36.21 degree.

The angle of view of the contrast test field of view is unchanged in thevertical direction, and the angle of field deformation in the horizontaldirection comparison is: 36.21/27.04=1.339.

In such an embodiment, the actual width ratio is in the range of2.35-2.40, so the anamorphic ratio is 1.33. For example, the horizontalfield of view angle is increased by 33%, so that 1.33 times anamorphicshooting may be achieved.

According to embodiments of the invention, when the anamorphic lensaccording to aspects of the invention is manufactured, the length of theanamorphic lens itself is less than 105 mm, with a maximum outerdiameter less than 70 mm, and a mass less than 600 g. Such dimension isfar smaller than similar type photographic camera interchangeablelenses, and, at the same time, it is far smaller than the professionalcinema anamorphic lenses of the same specifications on the market.

In a further embodiment, no limitation is directed to the materials usedfor the lenses. For example, embodiments of the invention may useoptical grade glasses for the lenses.

Moreover, the lens of the present application may be designed to becompatible with the bayonet of various brands of camera in the marketaccording to the actual use's specification, so as to achievepersonalized customization and universal use.

Example 2

Embodiments of the invention may provide a 50 mm focal length half-frameanamorphic lens with large aperture. In one example, Example 2 differsfrom the Example 1, as shown in FIG. 3 and FIG. 4, in that the combinedlenses of the fifth lens 5 and the sixth lens 6 may be two independentlenses. In one aspect, the fifth lens 5 may be a positive optical powermeniscus spherical lens, and the concave surface of the fifth lens 5 mayface the image side. In one embodiment, the sixth lens 6 may be anegative optical power meniscus spherical lens and the concave surfaceof the sixth lens 6 may face the image side.

In this Example, as compared to Example 1, as the fifth lens 5 and thesixth lens 6 may be independent, the anamorphic lens may comprise 10lenses, a group of 8.

In a further embodiment, on the basis of Example 1, the fifth lens 5 andthe sixth lens 6 may be replaced. Once replaced, the optical path may bealtered. As such, the lens type or shape may be adjusted accordingly tosatisfy the optical power of Example 1. As such, such adjustments, whilemay try to distinguish over the present invention to change the lenstype, shape or number, still falls within the spring and scope of thepresent invention.

Obviously, the foregoing embodiments may merely be an example with cleardescription and not as a limitation. For those of ordinary skill in theart, other different forms of changes or modifications may be made onthe basis of the above description. There is no need and cannot beexhaustive to illustrate all implementations. However, the obviouschanges or variations introduced thereby are still within the protectionscope created by the present invention.

1: An anamorphic lens comprising: an anamorphic group (11) comprisingcylindrical lenses; an imaging group (12) comprising spherical lenses,wherein the anamorphic group and the imaging group are disposed withrespect from an object side to an image side; wherein the anamorphicgroup (11), from the object side to the image side, sequentiallyarranges a first lens (1), a second lens (2), and a third lens (3),wherein the first lens (1) comprises a negative optical powercylindrical lens, wherein the second lens (2) comprise a negativeoptical power cylindrical lens, and wherein the third lens (3) comprisesa positive optical power cylindrical lens 2: The anamorphic lensaccording to claim 1, wherein the first lens (1) comprises a negativeoptical power biconcave cylindrical lens. 3: The anamorphic lensaccording to claim 1, wherein the second lens (2) and the third lens (3)are configured to be laminated together. 4: The anamorphic lensaccording to claim 3, wherein the second lens (2) and the third lens (3)are configured to be joined together. 5: The anamorphic lens accordingto claim 1, wherein the imaging group (12), from the object side to theimage side, sequentially arranges lens a fourth lens (4), a fifth lens(5), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninthlens (9), and a tenth lens (10), wherein the fourth lens (4) comprises apositive optical power meniscus spherical lens, wherein the seventh lens(7) comprises a negative optical power spherical lens, wherein theeighth lens (8) comprises a positive optical spherical lens, wherein theninth lens (9) comprises a positive optical power biconvex sphericallens, and wherein the tenth lens (10) comprises a positive optical powermeniscus spherical lens. 6: The anamorphic lens according to claim 5,wherein the seventh lens (7) and the eighth lens (8) are configured tobe laminated together. 7: The anamorphic lens according to claim 5,wherein the fifth lens (5) and the sixth lens (6) are configured to belaminated together, wherein the fifth lens (5) comprises a positiveoptical power spherical lens and the sixth lens (6) comprises a negativeoptical power lens. 8: The anamorphic lens according to claim 5, whereinthe fifth lens (5) and the sixth lens (6) comprise independent lenses,wherein the fifth lens (5) comprises a positive optical power meniscusspherical lens and the sixth lens (6) comprises a negative optical powermeniscus spherical lens, and wherein a concave surface of the fifth lens(5) and a concave surface of the sixth lens (6) face the image side. 9:The anamorphic lens of claim 1, wherein lenses in the anamorphic group(11) and lenses in the imaging group (12) are configured to satisfyfollowing relationships:500<abs(f ₁₋₃ /f ₄₋₁₀);45<f ₄₋₁₀<55;1.60<f ₄₋₆ /f ₄₋₁₀<2.10; and0.60<f ₇₋₁₀ /f ₄₋₁₀<0.80. 10: The anamorphic lens of claim 9, whereinlenses in the anamorphic group (11) and lenses in the imaging group (12)are further configured to satisfy following relationships:1.10<abs(f ₁ /f ₂₋₁₀)<1.40;−0.80<f ₁ /f ₂₋₃<−0.70;0.60<f ₄ /f ₄₋₆<0.90;1.0<f ₉₋₁₀ /f ₇₋₁₀<1.60; and5.0<abs(f ₇₋₈ /f ₇₋₁₀)<9.0. wherein f comprises a focal length of lensesin an X direction, where the subscript number of f represents a numberof the 10th lenses of the anamorphic lens, thus f₁ comprises the focallength in the X direction of the first lens, and f₁₋₁₀ comprises thecombined focal length of the first to 10th lenses in the X direction often lenses. 11: The anamorphic lens according to claim 1, wherein alength of the anamorphic lens is less than 105 mm, and a maximum outerdiameter of the anamorphic lens is less than 70 mm. 12: The anamorphiclens according to claim 1, wherein the anamorphic lens has a focallength in a Y direction of 50 mm and an aperture of f/stop of 1.8. 13:The anamorphic lens according to claim 1, wherein a mass of theanamorphic lens is less than 600 gram (g).